JP4207624B2 - Toilet bowl cleaning device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toilet cleaning device that detects urination of a user and supplies cleaning water to the toilet.
[0002]
[Prior art]
Conventional toilet flushing devices detect that the user has stood in front of the urinal with an infrared sensor, and after urination, when the user leaves, the flush valve is activated to flush the flushing water into the toilet. It was. However, such an automatic cleaning system based on human detection detects only human approaching and separation and flows a certain amount of washing water regardless of the presence or absence of urination and the amount of urine. Was wasted.
[0003]
In view of this, an apparatus has been developed that directly detects the urine flow speed during urination by using the Doppler effect of radio waves generated by microwaves and starts supply of wash water (see, for example, Patent Document 1). In the toilet described in Patent Document 1, a urine velocimeter using a Doppler sensor is installed in the upper part of the urinal, and detection radio waves are transmitted toward the lower part of the toilet. When an adult male urinates in this toilet, the urine flow is located above the toilet and the distance from the urine velocimeter to the urine flow is relatively small, so no problem occurs.
[0004]
However, when a boy with a short stature urinates in this toilet, the urine flow may be undetectable because the urine flow is at a low position and the distance from the urinometer to the urine flow becomes large. To deal with such problems, it is only necessary to increase the detectable distance by increasing the output of the radio wave emitted by the Doppler sensor. However, the radio wave output cannot be increased from a certain value due to regulations of the Radio Law. It's real.
[0005]
Therefore, there is a Doppler sensor arranged at the lower part of the toilet and transmitting a detection radio wave obliquely upward (see, for example, Patent Document 2). With such a urinal, even a urine flow at a low position of a boy can be captured by a Doppler sensor.
[0006]
In the method of detecting urine flow, the output signal of the Doppler sensor is output as an analog signal, so the control microcomputer takes in the output signal of the Doppler sensor from the A / D port, calculates the signal intensity inside the microcomputer, If a signal exceeding the threshold value continues for a certain period of time, it is regarded as detection of urine flow, and an electromagnetically driven flash valve is operated so that flush water flows into the urinal.
[0007]
[Patent Document 1]
Japanese Utility Model Publication No. 2-69760 (page 4-6, Fig. 1)
[Patent Document 2]
JP 2002-285626 A (page 3-5, FIG. 5)
[0008]
[Problems to be solved by the invention]
As in the urinal described in Patent Document 2, when the Doppler sensor is arranged in the lower part of the toilet and the radio wave is transmitted obliquely upward, if there is a fluorescent lamp or the like on the extension line, noise emitted from the fluorescent lamp is It is mixed in the receiving part and the influence of noise appears on the output signal of the sensor.
[0009]
The control microcomputer detects only the intensity of the output signal of the sensor, and even if noise from a fluorescent lamp or the like is mixed, it cannot be distinguished, so the noise is falsely detected even though there is no urine flow Then, the flush valve may be opened to flush the washing water.
[0010]
The problem to be solved by the present invention is to provide a toilet cleaning device that does not malfunction due to noise from a fluorescent lamp or the like and can eliminate the waste of cleaning water.
[0011]
[Means for Solving the Problems]
  The toilet bowl cleaning device of the present invention includes a water supply valve for supplying cleaning water into the toilet bowl, a transmission means for transmitting radio waves for detecting urine flow,SaidReceiving means for receiving a reflected wave of the radio wave transmitted by the transmitting means;SaidThe frequency of the radio wave transmitted by the transmission means andSaidA Doppler sensor that generates an output signal based on the frequency of the radio wave received by the receiving means;SaidA bandpass filter that selects and outputs only a specific frequency range from the output signal from the Doppler sensor;SaidIf the intensity of the output signal of the bandpass filter is above a certain thresholdSaidOpen the water supply valveSaidIn the toilet bowl cleaning device provided with a urine flow determination means for supplying cleaning water into the toilet bowl,SaidRemove noise contained in bandpass filter output signalSuitableResponse filterThe adaptive filter sequentially stores the output signal of the Doppler sensor at regular time intervals, delays the output signal stored in the past, and outputs the output signal of the Doppler sensor and the delay The noise included in the output signal of the Doppler sensor is removed based on the output signal of the circuit, and the current output signal and the antiphase signal are output to the adaptive filter based on the past output signal output from the delay circuit. Based on a part of the signal output from the signal adder circuit, the digital filter that generates the signal, the signal adder circuit that adds the antiphase signal generated by the digital filter to the output signal of the Doppler sensor, and outputs the added signal. Filter coefficient updating means for updating the filter coefficient of the digital filter is provided.It is characterized by that.
[0012]
By adopting such a configuration, it becomes possible to remove noise included in the output signal of the band-pass filter, that is, noise caused by radio waves other than the reflected wave received by the receiving means of the Doppler sensor by mistake. Since the output signal of the band pass filter is a signal that reliably captures the presence or absence of urine flow, the water supply valve does not malfunction due to noise from a fluorescent lamp or the like, and the waste of washing water can be eliminated. The output signal generated by the Doppler sensor based on the frequency of the radio wave transmitted by the transmitting means and the frequency of the radio wave received by the receiving means includes, for example, the frequency of the radio wave transmitted by the transmitting means and the radio wave received by the receiving means. An output signal (difference signal) corresponding to the difference from the frequency can be used, but a detection signal can be generated based on the frequency of the radio wave described above.
Here, if a notch filter is provided, an excellent removal function for noise having an amplitude peak at one frequency that can be known in advance within the target frequency band is exhibited. Also, if an adaptive filter is provided, noise can be accurately removed according to the state of noise generation even when the noise frequency cannot be known in advance.
[0014]
In this case, it is desirable that the noise removing unit has a function of removing noise having a frequency of 50 Hz to 240 Hz. By having such a function of removing noise in the frequency domain, it is possible to efficiently remove noise from a fluorescent lamp that is frequently used as a lighting fixture at a toilet installation location and is a relatively powerful noise generation source. Therefore, malfunctions can be almost eliminated, thereby saving toilet flushing water.
[0016]
When the Doppler sensor detects urine flow without noise, the waveform of the urine flow signal has a random shape. On the other hand, the noise from the fluorescent lamp has a periodic waveform shape due to the commercial power supply frequency. The autocorrelation function of the urine flow signal appearing in the output signal of the Doppler sensor is maximum at time 0 and tends to decrease rapidly as the delay time increases. Therefore, by providing a delay circuit in front of the adaptive filter and inputting the output signal of the delay circuit to the adaptive filter, the random urinary flow signal generated in the output signal of the Doppler sensor is removed, and the periodicity included in the urine flow signal Noise with noise can be emphasized.
[0017]
The number of delay elements constituting the delay circuit is preferably about 1 to 20. This makes it possible to obtain an efficient and reliable delay action and economically remove periodic noise. Can do.
[0018]
Here, the digital filter has a function of emphasizing and generating only the periodic component based on the past output signal output from the delay circuit, thereby only the periodic noise mixed in the output signal of the Doppler sensor. Can be output with emphasis.
[0019]
The signal adder circuit has a function of adding an antiphase signal of periodic noise generated by the digital filter to the output signal of the Doppler sensor and outputting the signal, and the urine flow signal included in the output signal of the Doppler sensor It is possible to remove only periodic noise from the mixed signal of noise.
[0020]
Further, the filter coefficient updating means has a function of dynamically updating the filter coefficient of the digital filter for each sampling of the signal based on a part of the signal output from the signal adding circuit, and thereby the noise frequency. Regardless of the amplitude and phase, only periodic noise can be optimally emphasized according to the characteristics of the noise.
[0021]
As described above, the delay circuit and the adaptive filter are provided, and the digital filter, the signal addition circuit, and the filter coefficient updating means are provided in the adaptive filter, so that the malfunction of the water supply valve due to noise from a fluorescent lamp can be avoided more reliably. Will be able to.
[0022]
Also, when the water supply valve is opened and wash water flows into the toilet bowl, the wash water is also detected by the Doppler sensor and is input to the adaptive filter as a signal larger than the urine flow signal. When an excessive signal is input, the filter coefficient is greatly disturbed accordingly. Therefore, while the cleaning water is flowing, the amplitude of the output signal of the Doppler sensor becomes very large, the filter coefficient of the adaptive filter is greatly disturbed, and the noise removal function after the cleaning is completed may be deteriorated.
[0023]
Therefore, it is desirable to provide the adaptive filter with a function of stopping the filter coefficient updating means while the water supply valve is open. As a result, the filter coefficient is not updated while the water supply valve is open and the cleaning water is flowing, so the filter coefficient is stabilized, the deterioration of the noise removal function after cleaning is avoided, and malfunction is eliminated. be able to.
[0024]
Here, the filter coefficient update means includes a step size μ multiplied by the output signal of the adaptive filter while the water supply valve is closed, and a filter coefficient calculator that calculates the filter coefficient according to the step size μ. During the opening of the water supply valve, it is desirable to provide a function of using the step size γ within the range of 0 <γ <μ instead of the step size μ. By providing such a function, even if an excessive input signal is generated during cleaning, the filter coefficient is not greatly disturbed, so that a reduction in the noise removal function after cleaning is avoided and no malfunction occurs.
[0025]
Further, it is desirable to provide a function of closing the water supply valve after all the filter coefficients are set to 0 after the water supply valve is opened. If such a function is provided, even if an excessive input signal is generated during cleaning and the filter coefficient is greatly disturbed, the filter coefficient is updated again from a small value. The filter coefficient is stable, and malfunctions can be eliminated.
[0026]
Furthermore, it is desirable to provide a function of stopping the urine flow determination means for a certain time after the water supply valve is opened. If such a function is provided, even if an excessive detection signal is generated during washing and the filter coefficient may be greatly disturbed, the urine flow judging means stops during that time, so that malfunction after washing can be eliminated. it can. The fixed time is preferably about 3 to 40 seconds.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing a toilet bowl cleaning device according to an embodiment of the present invention, FIG. 2 (a) is a pattern diagram showing horizontal directional characteristics of a Doppler sensor that constitutes the toilet bowl cleaning device shown in FIG. FIG. 2B is a pattern diagram showing the directivity characteristics in the vertical direction of the Doppler sensor, and FIG. 3 is a side view showing a use state of the urinal constituting the toilet flushing apparatus shown in FIG.
[0028]
As shown in FIG. 1, the toilet bowl cleaning device of the present embodiment includes a water supply valve 11 that supplies cleaning water supplied from a water supply pipe 12 into the urinal 10, and an obliquely inclined front side to front side of the urinal 10. The transmitting means 5 for emitting the radio wave 7 from the transmitting antenna 5a upward, the receiving means 6 for receiving the reflected wave 8 of the radio wave 7 transmitted by the transmitting means 5 through the receiving antenna 6a, and the radio wave 7 transmitted by the transmitting means 5 A Doppler sensor 34 including a difference detection unit 4 that generates an output signal corresponding to the difference between the frequency and the frequency of the reflected wave 8 received by the reception unit 6 is provided.
[0029]
Further, a band pass filter 3, a delay circuit 38, an adaptive filter 2, a urine flow determination unit 1, a water supply valve control unit 39, and the like are provided at the subsequent stage of the Doppler sensor 34. The adaptive filter 2 includes a digital filter 40, a signal addition circuit 41, a filter coefficient update circuit 42, and the like.
[0030]
The output signal of the Doppler sensor 34 is sent to the adaptive filter 2 directly and via the delay circuit 38, and the output signal after a predetermined process described later is performed by the adaptive filter 2 is sent to the urine flow determination unit 1. If the intensity of the output signal is equal to or greater than a certain threshold value, the water supply valve control unit 39 opens the water supply valve 11 and allows the wash water supplied from the water supply pipe 12 to flow to the urinal 10. As described above, in the present embodiment, the output signal (difference signal) is generated according to the difference between the frequency of the radio wave 7 transmitted by the transmission unit 5 and the frequency of the radio wave 8 received by the reception unit 6. However, the detection signal may be generated based on the frequency of the radio waves 7 and 8 described above.
[0031]
Here, the directivity characteristics of the Doppler sensor 34 will be described with reference to FIGS. The flow rate and direction of the urine flow 33 when the user 31 urinates toward the urinal 10 does not vary much in the horizontal direction but tends to vary greatly in the vertical direction. Accordingly, the directivity characteristics of the Doppler sensor 34 for detecting the urine flow 33 are set so that the horizontal direction is narrow as shown in FIG. 2A and the vertical direction is wide as shown in FIG. Has been.
[0032]
As shown in FIG. 3, the Doppler sensor 34 is attached to the lower part of the back surface of the urinal 10, and has a directional characteristic that extends obliquely upward toward the front surface of the standing user 31. This is for reliably detecting even a urine flow having a low position and a low flow rate, such as the urine flow of a boy with a short stature. In order to capture the urine flow 33 with certainty, the Doppler sensor 34 is installed near the center of the urinal 10 in the height direction so that the directional characteristic spreads in the horizontal direction or the directional characteristic spreads obliquely downward. May be installed.
[0033]
When the user 31 stands in a predetermined position and urinates toward the urinal 10, the urine flow 33 of the user 31 is detected by the Doppler sensor 34, and after being subjected to the signal processing as described above, it is provided in the middle of the water supply pipe 12. The supplied water supply valve 11 is opened, the washing water is poured down the wall surface of the urinal 10, and the urinal 10 is washed.
[0034]
In the present embodiment, the urine flow 33 of the user 31 is detected by the Doppler sensor 34 using microwaves. The Doppler sensor 34 emits a radio wave 7 (for example, 10.525 GHz) in a microwave band radially from the transmitting antenna 5a, and receives a radio wave (reflected wave 8) reflected by the urine flow 33 as a measurement object. The Doppler wave component generated between the transmitted wave (radio wave 7) and the received wave (reflected wave 8) is taken out and the velocity of the urine flow 33 is generally measured. That is, the velocity of the urine flow 33 can be estimated from the Doppler frequency ΔF generated between the transmitted wave (radio wave 7) and the received wave (reflected wave 8).
[0035]
When the urine flow 33 is measured by the Doppler sensor 34, it is observed as a spectrum having a certain frequency spread rather than a line spectrum having a sharp peak at a specific frequency. This is because the movement of any water flow including the urine flow that flows through the wall surface of the urinal 10 is observed. In addition, as shown in FIG. 12 mentioned later, it turns out that the urine flow 33 observed with the Doppler sensor 34 has the characteristic of having a big peak especially in 100 Hz-200 Hz.
[0036]
In the present embodiment, the radio wave 7 is radiated toward the urine flow 33 of the user 31 by the transmitting antenna 5a. The radio wave 8 reflected by the urine flow 33 is taken into the receiving means 6 via the receiving antenna 6a, and the difference detection means 4 takes out the difference between the two radio wave signals of the transmitted radio wave 7 and the received reflected wave 8. The Doppler frequency component Fs is sent to the band pass filter 3. The band pass filter 3 extracts only frequency components of 100 Hz to 200 Hz, which are the characteristics of the urine flow 33, from the Doppler frequency component Fs. The signal that has passed through the band pass filter 3 is transmitted to the signal adding circuit 41 and the delay circuit 38 of the adaptive filter 2. An amplitude power component is taken out by the microcomputer 1, and a urine flow is detected if the amplitude power equal to or greater than the threshold value continues for a certain time.
[0037]
On the other hand, it is known that the fluorescent lamp 9 frequently used as a lighting fixture at the place where the urinal 10 is installed generates noise 35. Therefore, when the fluorescent lamp 9 exists in the directional characteristic pattern of the Doppler sensor 34 shown in FIGS. 2 and 3, the Doppler sensor 34 detects the noise 35 emitted from the fluorescent lamp 9, and the output signal includes noise. 35 appears together.
[0038]
FIG. 4 shows a signal waveform of the noise 35 of the fluorescent lamp 9 received by the Doppler sensor 34 in an area where the commercial power supply frequency is 60 Hz. According to this figure, it can be seen that the characteristics of the noise 35 generated from the fluorescent lamp 9 include a certain degree of periodicity, and waveform distortion and large undulations are observed in some places instead of a complete sine wave.
[0039]
Here, FIG. 5 shows the signal waveform shown in FIG. 4 converted into a frequency spectrum. The frequency spectrum of the noise 35 of the fluorescent lamp 9 has a peak at 120 Hz as a maximum amplitude peak, which is twice as high as 240 Hz, and further at 20 Hz and twice as high as 40 Hz and three times as high as 60 Hz. As described above, the noise 35 of the fluorescent lamp 9 has 120 Hz as a basic component, but its n-order harmonic component, a frequency not directly related to the power supply frequency, and its n-order harmonic component are combined in a complex manner. It can be seen that the waveform has been changed. However, noise with a frequency of 50 Hz to 240 Hz in the range of the fundamental frequency of the commercial power supply and its second harmonic, which is caused by the commercial power supply frequency, is particularly problematic, and it is necessary to remove noise in this range.
[0040]
As described above, since the Doppler sensor 34 for detecting the urine flow 33 has a wide directional characteristic pattern in the vertical direction, when the noise 35 from this direction is received, the influence of the Doppler sensor 34 is an output signal of the Doppler sensor 34. Appears in For example, in FIG. 3, the radiation center of the radio wave 7 emitted from the Doppler sensor 34 is directed obliquely upward at an angle of 45 degrees from the horizontal plane, so that the urine flow 33 can be easily captured. At this time, the vertical direction directivity pattern of the Doppler sensor 34 is like the directivity pattern 32 shown in FIG. 3, which is a directivity pattern extending from the floor to the ceiling.
[0041]
By the way, a Doppler sensor 34 can be attached near the center in the height direction on the back surface of the urinal 10 to emit radio waves in the horizontal direction. However, even if such a method is adopted, the directional characteristic pattern of the sensor is wide in the vertical direction as shown in FIG. 3, so that the noise of the fluorescent lamp in the diagonally upward direction is hardly attenuated. Incident. That is, even if the arrangement position or direction of the Doppler sensor 34 is devised, the actual situation is that the influence of the noise 35 cannot be avoided.
[0042]
Here, a case where the adaptive filter 2 is used will be described. In order to take out only the frequency component of the urine flow 33, the band pass filter 3 shown in FIG. On the other hand, the noise 35 of the fluorescent lamp 9 received by the Doppler sensor 34 has a large peak at 120 Hz as shown in FIG. Therefore, the noise 35 easily passes through the band pass filter 3, and as shown in FIG. 15, a noise peak appears in the required frequency range, and the noise 35 is erroneously detected as the urine flow 33. Therefore, in the present embodiment, the adaptive filter 2 is provided in order to remove noise components that have passed through the band pass filter 3.
[0043]
On the other hand, for example, a notch filter is also effective as means for removing noise components that have passed through the band pass filter 3. As shown in the frequency characteristic diagram of the filter in FIG. 16, only a specific frequency is selected and attenuated. If the noise frequency is known, the noise can be efficiently removed by selecting the noise characteristics so as to selectively attenuate the frequency. If the urine flow detection frequency range is sufficiently wider than the notch filter frequency selection range, even if the noise frequency portion is attenuated, urine flow detection is not significantly affected.
[0044]
Unlike the above, when the noise frequency is not known, it is necessary to change the selection frequency according to the noise. For example, when the second harmonic of a commercial power supply appears in noise, it is necessary to change the frequency according to the West Japan region (120 Hz), the East Japan region (100 Hz), and the region. Furthermore, when noise components having a plurality of frequencies are found in the target urine flow frequency range, a single notch filter cannot be used, and therefore a plurality of notch filters are used. Therefore, in the present embodiment, the adaptive filter 2 is provided in order to effectively remove noise according to the noise situation even if the frequency is not known or a plurality of noises.
[0045]
Here, the operation of the toilet bowl cleaning device of the present embodiment will be described with reference to the flowcharts of FIGS. When the user 31 approaches the urinal 10 and stands in front of the urinal 10 to urinate and then moves away from the urinal 10, the Doppler sensor 34 causes the urine flow 33 of the user 10 to flow. The sensor signal is always detected and the amplitude of the sensor signal detected by the Doppler sensor 34 is compared with a threshold value. If the threshold value is less than or equal to the threshold value, the determination of the sensor signal is continued. It is determined whether or not to continue.
[0046]
In this case, if the urine flow 33 stops within 0.5 seconds, the amplitude of the sensor signal is compared again with the threshold value. If the urine flow 33 continues for 0.5 seconds or more, the flush water supply valve 11 is turned on for 3 seconds. Open and supply flush water into the urinal 10. Thereafter, the threshold value of the sensor signal is determined again. In this manner, the urinal 10 is cleaned by the Doppler sensor 34 detecting the urine flow 33 of the user 31.
[0047]
FIG. 13 is a block diagram showing the configuration of the toilet bowl cleaning device of this embodiment. As shown in FIG. 13, the Doppler signal sent from the Doppler sensor 34 is sent to the control unit 43. When the noise 35 of the fluorescent lamp 9 is mixed in the detection signal of the Doppler sensor 34, a noise component is also mixed in the Doppler signal sent from the Doppler sensor 34. Therefore, the Doppler signal captured by the control unit 43 is sent to an A / D converter 46 inside the microcomputer 45 after an analog LPF (Low Pass Filter) 44 deletes a frequency high-frequency component in accordance with the sampling frequency. .
[0048]
The Doppler signal sampled by the A / D converter 46 is limited to the frequency band (100 Hz to 200 Hz) of the urine flow detection component by the band pass filter 3 and then sent to the adaptive filter 2. At this time, noise 35 is included in the Doppler signal transmitted to the input unit of the adaptive filter 2, but the noise 35 is removed by the adaptive filter 2 and sent to the amplitude determination unit 48.
[0049]
The amplitude determination unit 48 sequentially calculates the moving average of the amplitude of the input signal. When the moving average value calculated by the amplitude determination unit 48 is larger than a preset amplitude determination threshold 47 and continues continuously for a certain period of time, the urine flow determination unit 1 determines that the urine flow 33 is present, The water supply valve control unit 39 opens the water supply valve 39 for a certain period of time and supplies cleaning water to the urinal 10.
[0050]
Here, with reference to FIG. 6, the noise removal function in the toilet bowl cleaning apparatus of the present embodiment will be described. As described above, the detection signal of the urine flow 33 includes a lot of frequency components between 100 Hz and 200 Hz, but is a random signal when viewed on the time axis. This is because the Doppler sensor 34 detects various water flows formed by the urine flow moving or pulsating including the water flow flowing on the wall surface.
[0051]
On the other hand, the noise 35 of the fluorescent lamp 9 mixed in the Doppler signal from the Doppler sensor 34 is a periodic signal having a frequency of about 120 Hz, although the waveform shape is complex, and strongly depending on the commercial power supply frequency. That is, the Doppler signal mixed with the noise 35 of the fluorescent lamp 9 is a mixture of a periodic signal and a random signal. Therefore, if only the periodic component of the Doppler signal is predicted by the adaptive filter 2 and subtracted from the observed Doppler signal, only the random frequency component, that is, the detected component of the urine flow 33 can be obtained. In this way, the noise 35 of the fluorescent lamp 9 which is a periodic component is effectively removed by the adaptive filter 2.
[0052]
Furthermore, with reference to FIG. 6, the removal function of the noise 35 of the fluorescent lamp 9 by the adaptive filter 2 will be described in detail. As described above, noise can be effectively removed by generating a noise prediction signal that is a periodic component using the adaptive filter 2. Therefore, in the present embodiment, the delay circuit 38 is arranged in the previous stage of the adaptive filter 2 in order to predict the periodic component. Since the detection signal of the urine flow 33 is a random signal, its autocorrelation function is maximized when the delay is 0, and decreases as the delay increases.
[0053]
On the other hand, the amplitude of the periodic signal such as the noise 35 of the fluorescent lamp 9 increases not only when the delay is 0, but also in the delay time corresponding to the period. That is, if the 0-hour signal component is removed, a random component such as the detection signal of the urine flow 33 is removed, and only the noise periodic component is emphasized. In the present embodiment, as shown in FIG. 10, a random component, that is, a urinary flow signal is surely removed from the output signal of the Doppler sensor 34 by providing a delay circuit 38 of 10 stages before the adaptive filter 2. The delay element 38a constituting the delay circuit 38 may be at least one stage.
[0054]
Next, the function and operation of the adaptive filter 2 in the toilet bowl cleaning device of the present embodiment will be described in more detail with reference to FIGS.
[0055]
As shown in these drawings, the input signal x [n] of the Doppler signal input from the band pass filter 3 is input to the delay circuit 38 described above. Z^-1Represents Z conversion and is equivalent to a delay circuit. In the present embodiment, the delay circuit 38 is composed of 10 stages of delay elements 38a. Since the delay circuit 38a sends the input signal value to the next stage every sampling time, the input signal x [n] output from the delay circuit 38 of this embodiment is equal to the input signal before 10 sampling.
[0056]
In the present embodiment, the adaptive filter 2 includes a digital filter 40, a signal addition circuit 41, and a filter coefficient update circuit 42. The digital filter 40 receives a signal sent from the delay circuit 38 and outputs a noise prediction waveform y [n]. In the present embodiment, a 64-stage FIR type digital filter is used as the digital filter 40. The filter coefficients h0 to h63 of the FIR type digital filter are multiplied with each stage of each corresponding delay element, and the sum of the results is calculated to obtain the output signal y [n]. The filter coefficients h0 to h63 are adjusted in advance by a filter coefficient update circuit 42 described later so as to extract only periodic component signals such as noise 35 of the fluorescent lamp 9 included in the input signal, and the output signal y [n] is The signal is optimal for noise removal.
[0057]
The signal adding circuit 41 adds an inverted signal of the output signal y [n] of the digital filter 40, that is, -y [n], which is an antiphase signal, to the input signal x [n]. As described above, y [n] is a periodic component signal included in the input signal, that is, a periodic component signal such as the noise 35 of the fluorescent lamp 9, and as a result, an antiphase signal of periodic noise is input to the input signal x. [N] is added.
[0058]
The addition result ε [n] is only the signal component of the random urine flow 33 obtained by removing periodic noise such as the noise 35 of the fluorescent lamp 9 from the input signal x [n]. Thereafter, the addition result ε [n] is sent to the urine flow determination unit 1 and used as a signal for urine flow determination. Since the periodic noise prediction signal y [n] of the digital filter 40 does not completely match the noise component of x [n], the addition result ε [n] does not become zero.
[0059]
Next, the filter coefficient update circuit 42 has a function of adjusting the filter coefficients h0 to h63 of the digital filter 40 so as to minimize the above-described addition result ε [n]. In this embodiment, an LMS (Least Mean Square) method capable of simplifying the calculation process is used as a coefficient updating method of the adaptive filter 2. According to this LMS method, the noise prediction error ε [n] is multiplied by twice the step size μ49, and further multiplied by each input signal x [n] at the current time, and each filter coefficient h [n] at the current time. ] To obtain each filter coefficient h [n + 1] at the next time.
[0060]
According to this method, although the absolute value of the residual ε [n] is large at the calculation start time, the absolute value of ε [n] converges to 0 as time elapses. Here, the step size μ49 is a parameter for determining the speed of convergence and the amount of error after convergence. Generally, a value of 0 <μ <1 is set.
[0061]
Also in the band pass filter 3 of this embodiment, the FIR type digital filter is used as described above. Here, the filter coefficient h [n] is set so as to extract 100 Hz to 200 Hz, which is the detection range of the urine flow 33. Note that an analog filter that does not have a digital processing function, for example, a band-pass filter using an analog circuit may be used instead of the LPF unit 44 in FIG. Furthermore, even if the order of the bandpass filter 3 and the adaptive filter 2 is exchanged and the adaptive filter 2 and the bandpass filter 3 are arranged in this order, the same function and effect can be obtained.
[0062]
In this embodiment, the A / D conversion sampling period is 2 ms, that is, the sampling frequency is 500 Hz. Since the sampling theorem is effective for signals having a frequency less than half of the sampling frequency, the effective frequency of this embodiment is 250 Hz or less, and a urine flow signal having a large peak at 100 Hz to 240 Hz is within the range of the effective frequency. . The frequency of the noise 35 of the fluorescent lamp 9 passing through the band pass filter 3 is 120 Hz (in the case where the commercial power supply frequency is 60 Hz). In this embodiment, periodic noise removal by the adaptive filter 2 is effective in a frequency band in the range of about 10 Hz to 250 Hz of the sampling frequency, and it has been confirmed that 120 Hz fluorescent lamp noise can be largely removed.
[0063]
Next, the removal result of the noise 35 of the fluorescent lamp 9 included in the Doppler signal will be described with reference to FIG. As shown in FIG. 7, large periodic noise is seen in the Doppler signal x [n]. When the signal -y [n] having the opposite phase to the noise prediction signal y [n] is added to this, the error component ε [n] remains after the noise is largely removed. In this embodiment, a noise reduction of about 20 dB was confirmed.
[0064]
FIG. 8 shows the waveform of the Doppler signal x [n] before noise removal observed on a longer time axis. The portion of 0 to 20 seconds and 55 seconds to 100 seconds is a portion where noise is mixed. Further, the portion of 20 seconds to 55 seconds is a portion where the user 31 approaches the urinal 10 and the urine flow 33 is detected. FIG. 9 shows the Doppler signal ε [n] after noise removal. This is a signal waveform after noise removal by the adaptive filter 2 at the same time as in FIG. Compared to FIG. 8, it can be confirmed that the amplitudes of 0 to 20 seconds and 55 to 100 seconds are greatly attenuated.
[0065]
As described above, the toilet bowl cleaning device of the present embodiment includes the delay circuit 38 and the adaptive filter 2, and the adaptive filter 2 includes the digital filter 40, the signal addition circuit 41, and the filter coefficient update circuit 42. The noise 35 from the fluorescent lamp 9 could be removed, thereby eliminating the malfunction of the toilet bowl cleaning device.
[0066]
On the other hand, when the adaptive filter 2 is used, generally, when a signal having a large amplitude is added to the input signal and then a signal having a small amplitude is added, the convergence of the system is deteriorated. In particular, in the adaptive filter 2 based on the LMS method, the output signal ε [n] multiplied by the step size 2μ is multiplied by the input signal to be used as an input for updating the filter coefficient. Therefore, the change width of the filter coefficient is the amplitude of the input signal. Once a large filter coefficient is stored, it takes time to converge to a filter coefficient corresponding to a signal having a small amplitude.
[0067]
In the toilet cleaning device of the present embodiment, the amplitude level of the output signal when the Doppler sensor 34 observes the urine flow 33 and the amplitude of the output signal when the wash water flowing in the urinal 10 is observed. When compared with the level, the amplitude level when the wash water flowing in the urinal 10 is observed is overwhelmingly larger. For this reason, when the urine flow 33 is detected, the cleaning valve 11 is opened, and the cleaning water is flowed, the filter coefficient greatly varies depending on the large amplitude level.
[0068]
In the toilet bowl cleaning apparatus of the present embodiment, after the cleaning valve 11 is closed and the cleaning water is stopped, noise removal is started by the adaptive filter 2. At the start time, the filter coefficient of the adaptive filter 2 has an amplitude of Since a large value is already stored to adapt to a large washing water, when noise removal for the next urine flow determination is performed, it takes time to converge because the filter coefficient is too large.
[0069]
Therefore, while the cleaning valve 11 is opened and the cleaning water is flowing, the function of the filter coefficient update circuit 42 for updating the coefficient h [n] of the filter coefficient of the adaptive filter 2 is stopped, and the coefficient h [n] The value of was kept. Accordingly, it is possible to avoid a decrease in the convergence speed of the adaptive filter 2 after the stop of the cleaning water without being affected by an excessive input of the Doppler sensor 34 while the cleaning water is flowing.
[0070]
Here, the operation of the adaptive filter 2 will be described with reference to FIG. The filter coefficient update circuit 42 includes a filter coefficient calculation unit 50 and a step size 49. The digital filter 40 has a filter coefficient 51 for storing the count value calculated by the filter coefficient calculation unit 50. The step size 49 is a parameter that determines the speed of convergence and the amount of error after convergence. The larger the value of the step size 49, the faster the convergence speed becomes. However, the residual after convergence becomes larger, and when the value of the step size 49 becomes smaller, the error after convergence becomes smaller, but the convergence speed tends to be slower. is there.
[0071]
  Therefore, two large and small step sizes μ and γ can be prepared and set so that 0 <γ <μ. The larger step size μ is used for the purpose of improving the convergence speed when the input signal is small, and the smaller step size γ is effective for the purpose of reducing the convergence error when the input signal is large. is there. Therefore, when the water supply valve 11 is opened and washing water is flowing, the input signal becomes large.smallStep sizeγTo improve the convergence speed when the cleaning valve 11 is closedlargeStep sizeμIs used. As a result, the filter function after flowing the washing water can be stabilized and the convergence speed can be increased.
[0072]
On the other hand, the change width of the filter coefficient 51 is proportional to the input signal, and once the filter coefficient 51 becomes large due to excessive input during cleaning, the change width is small for a small input signal after cleaning, and it takes time to converge. End up. Therefore, it is possible to provide a function of clearing all the coefficients to zero after the washing water is flown and the filter coefficient 51 of the adaptive filter 2 is greatly disturbed. By providing such a function, it is possible to stabilize the filter operation after flowing the washing water and to increase the convergence speed.
[0073]
In addition, if the filter coefficient is greatly disturbed after flushing water, it takes time to converge as described above, but since the amplitude is large in the convergence process, the urine flow is judged. Is inaccurate. Therefore, it is possible to provide a function of measuring the time elapsed after closing the washing valve 11 with a timer and not performing the urine flow detection determination within a preset time t. In this case, it has been empirically found that the convergence of the output signal of the adaptive filter 2 is not completed for 30 seconds at the maximum after the washing valve 11 is closed. Therefore, the use of the urinal can be determined more accurately.
[0074]
【The invention's effect】
The present invention has the following effects.
[0075]
(1) A band pass filter that selects and outputs only a specific frequency range from the output signal from the Doppler sensor, and if the intensity of the output signal of the band pass filter is above a certain threshold, the water supply valve is opened to open the toilet In the toilet flushing device provided with the urine flow judging means for supplying the wash water to the toilet, the noise removal means for removing the noise included in the output signal of the band pass filter is provided, so that malfunction occurs due to noise from a fluorescent lamp or the like. This eliminates the waste of washing water.
[0076]
(2) If a notch filter is provided as the noise removal means, it exhibits an excellent removal function for noise having an amplitude peak at one frequency that can be known in advance within the required frequency band. If it is provided, noise can be accurately removed according to the state of noise generation even when the frequency of noise cannot be known in advance.
[0077]
(3) Since the noise removing means has a function of removing noise having a frequency of 50 Hz to 240 Hz, the noise from a fluorescent lamp, which is a relatively powerful noise generating source, is frequently used as a lighting fixture in a toilet installation place. Therefore, malfunction can be almost eliminated.
[0078]
(4) By providing a delay circuit and an adaptive filter as the noise removing means, and providing the adaptive filter with a digital filter, a signal adding circuit, and a filter coefficient updating means, a water supply valve due to noise from a fluorescent lamp or the like Can be avoided more reliably.
[0079]
(5) Since the adaptive filter is provided with a function for stopping the filter coefficient updating means while the water supply valve is open, the filter coefficient is not updated while the water supply valve is open. The deterioration of the noise removal function is avoided, and malfunctions can be eliminated.
[0080]
(6) The filter coefficient update means includes a step size μ multiplied by the output signal of the adaptive filter while the water supply valve is closed, and a filter coefficient calculator that calculates the filter coefficient based on the step size μ. Even if an excessive input signal is generated during cleaning by providing the adaptive filter with a function that uses the step size γ within the range of 0 <γ <μ instead of the step size μ while the water supply valve is open, Since the filter coefficient is not greatly disturbed, a reduction in the noise removal function after cleaning is avoided and no malfunction occurs.
[0081]
(7) If the adaptive filter is provided with a function for closing the water supply valve after setting the filter coefficient to 0 after the water supply valve is opened, an excessive input signal is generated during cleaning, and the filter coefficient is greatly disturbed. Even if there is, the filter coefficient is updated again from a small value, so that the filter coefficient after cleaning becomes stable and malfunction can be eliminated.
[0082]
(8) If the adaptive filter is provided with a function of stopping the urine flow judging means for a certain period of time after the water supply valve is opened, an excessive detection signal may be generated during washing, and the filter coefficient may be greatly disturbed. However, since the urine flow judging means stops during that time, it is possible to eliminate malfunction after washing.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a toilet bowl cleaning apparatus according to an embodiment of the present invention.
2A is a pattern diagram showing the directivity characteristics in the horizontal direction of the Doppler sensor constituting the toilet flushing apparatus shown in FIG. 1, and FIG. 2B is a pattern diagram showing the directivity characteristics in the vertical direction of the Doppler sensor. is there.
FIG. 3 is a side view showing a usage state of the urinal shown in FIG. 1;
FIG. 4 is a waveform diagram showing noise from a fluorescent lamp.
FIG. 5 is a frequency spectrum diagram showing noise from a fluorescent lamp.
6 is a configuration diagram showing a part of the toilet bowl cleaning device shown in FIG. 1; FIG.
FIG. 7 is a waveform diagram showing a noise removal situation in the toilet bowl cleaning device shown in FIG. 1;
FIG. 8 is a waveform chart showing a Doppler sensor output signal before noise removal in the toilet bowl cleaning apparatus shown in FIG. 1;
FIG. 9 is a waveform diagram showing a Doppler sensor output signal after noise removal in the toilet bowl cleaning device shown in FIG. 1;
10 is a block diagram of an adaptive filter that constitutes the toilet bowl cleaning device shown in FIG. 1. FIG.
FIG. 11 is a flowchart showing an operation state of the toilet bowl cleaning device shown in FIG. 1;
12 is a spectrum diagram of a urine flow signal detected in the toilet bowl cleaning device shown in FIG. 1. FIG.
FIG. 13 is a block diagram of a control unit constituting the toilet bowl cleaning device shown in FIG. 1;
14 is a schematic block diagram of an adaptive filter constituting the toilet bowl cleaning device shown in FIG. 1. FIG.
FIG. 15 is a frequency spectrum of a urinary flow signal including noise.
FIG. 16 is a frequency characteristic diagram of a notch filter.
[Explanation of symbols]
1 Urine flow determination unit
2 Adaptive filter
3 Bandpass filter
4 Difference detection means
5 transmission means
6 Receiving means
7 radio waves
8 Reflected wave
9 Fluorescent lights
10 Urinal
11 Water supply valve
12 Water supply pipe
31 users
32 Directivity pattern
33 Urine flow
34 Doppler sensor
35 noise
36 Electromagnetic Radiation Center
38 Delay circuit
39 Water supply valve controller
40 Digital filter
41 Signal addition circuit
42 Filter coefficient update circuit
43 Control unit
44 LPF
45 Microcomputer
46 A / D converter
47 judgment threshold
48 Amplitude judgment unit
49 step size
50 Filter coefficient calculator
51 Filter coefficient

Claims (5)

A water supply valve for supplying flush water into the toilet, a transmitting means for transmitting radio waves for detecting urine flow, a receiving means for receiving reflected waves of radio waves transmitted by the transmitting means, and a radio wave transmitted by the transmitting means A Doppler sensor for generating an output signal based on the frequency and the frequency of the radio wave received by the receiving means;
A bandpass filter that selects and outputs only a specific frequency range from the output signal from the Doppler sensor;
In the toilet flushing device, comprising a urine flow judging means for opening the water supply valve and supplying flush water into the toilet if the intensity of the output signal of the bandpass filter is equal to or greater than a certain threshold value,
Comprises a adaptive filter to eliminate noise contained in the output signal of the band-pass filter,
The adaptive filter sequentially stores the output signal of the Doppler sensor at regular time intervals, delays the stored past output signal, and outputs the output signal of the Doppler sensor and the delay circuit. While removing the noise contained in the output signal of the Doppler sensor based on the output signal,
In the adaptive filter,
A digital filter that generates a current output signal and an antiphase signal based on the past output signal output by the delay circuit;
A signal addition circuit for adding the antiphase signal generated by the digital filter to the output signal of the Doppler sensor and outputting the signal;
A toilet cleaning apparatus, comprising: filter coefficient updating means for updating a filter coefficient of the digital filter based on a part of a signal output from the signal adding circuit . Wherein the adaptive filter, wherein during opening of the water supply valve the filter coefficient update means provided with a function of stopping claim 1 toilet cleaning device according. The filter coefficient updating means includes a step size μ that is multiplied by the output signal of the adaptive filter while the water supply valve is closed, and a filter coefficient calculator that calculates the filter coefficient based on the step size μ. It is, instead 0 <gamma <toilet cleaning device according to claim 1, wherein the step size the ability to use the gamma provided in the adaptive filter in the range of μ of an open step size μ of the water supply valve. Wherein the adaptive filter, wherein after after opening the water supply valve is that the filter coefficients 0, the toilet flushing apparatus of claim 1, wherein providing the ability to close the water supply valve. Wherein the adaptive filter, wherein after opening the water supply valve, is within a predetermined time the toilet flushing device according to claim 1, wherein providing the ability to stop the urine flow determining means.

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